Passing arguments to subclasses

[John Dann]

Thanks for the responses - they're much appreciated. And I understand
the slight impatience with questions that could possibly be answered
without recourse to a forum - I'm usually in the opposite position of
fielding many newbie questions in a forum in a completely different
field!

But don't be too harsh on this category of questions for a couple of
reasons. First, newbies don't necessarily yet have the same easy
familiarity with the Python interpreter that's implied. - personally
I'd be a little concerned as to whether any significant block of
test/example code that I'd entered into the interpreter was actually
addressing the exact question that I had in mind. 

And second, the answer might have been of the 'yes, but' kind. In
other words, it might perhaps have been true in a certain sort of
simple example, but one that failed to provide the complete picture.
So sometimes it's reassuring to be able to get an authoritative
answer.

Thanks again for taking the time to answer.